Safety lowering device



y l932- F. J. WINTERER ET AL 1,860,375

SAFETY LOWERING DEVICE Filed Dec. 6. 1-950 4 Shets-Shet 1 WITNESSES:INVENTORS v I Ii'ankLM/mt are]:

7! Arthur-E..Hc|' FE a 7 0 /f\ :11; zr I THE/R A TTORNE Y I May 31, 193F.- J. WINTERER ET AL 1,850,375

SAFETY LOWERING DEVICE Filed Dec. 6, 1950 4Sheets-Sheet 2 INVENTORS Irank ].Wmierer.,,

' ArihurE Hu r'EhE THE/R A TTORNEY 4? 31, 1932- F. J. WINTERER :1- AL ,3

I SAFETY LOWERING DEVICE v Q Filed Dec. 6, 1930 1 4 Sheets-Sheet 3 as I?W1 TN ESS E 5 INVENTORS IrankJ.\AAn+er'EY Arvhur'.Hm febe BY THEIRATTORNEY May 31, 1932. F. J. WINTERER ET AL SAFETY LOWERING DEVICE FiledDec. 6. 1950 4 Sheets-Sheet 4 WITNESS 5:

1 N V EN TORS V v E Q E v Vt m I m m U EH A .t .J m E w W- V. H U T Tm wTHAN Patented May 31, 1932 jumrao srAras PATENT OFFICE FRANK J. WINTERERAND ARTHUR E. EOGREBE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR8 TO BOXCRANE & HOIST CORPORATION, OF IHILADELPHIA, PENNSYIr- VANIA, ACORPORATION OF DELAWARE SAFETY LOWERING DEVICE Application filedDecember 6, 1930. Serial No. 500,564.

This invention relates to hoisting niachinery, and has particularreference to a safety lowering device for supporting the load.

In hoisting machinery, where the load is carried by a hook fastened to acable wound upon the drum, and that drum connected to power means suchfor instance asa motor, if the motor were to sto without the provisionof a load brake, or the like, the load would immediately drop to a placeof rest, rotating the drum which would in turn freely rotate the rotorof the motor.

In order that the load may be supported at any desired elevation whenthe hoisting motor stops, hoisting machinery is provided with deviceswhich prevent the load from rotating the drum. These devices are knownin different types of hoisting machinery as load brakeautomaticmechanical brake and still other names having similar meanings.

Any type of brake used widely in hoisting machinery employs a ratchetdevice, frictionally engaging means for supportin the load throughfriction plates or disks. hese disks are partially submerged in oil tolubricate the same, and to give them a long life by preventing thefrictional grinding of the same.

This invention relates to a safety lowering device, or load brake of thetype employing friction disks partially submerged in oil, or lubricatingfluid.

The ob'ect of the invention is to provide an improve safety loweringdevice.

A further object of the invention is to provide a safety lowering devicein which the slippage, due to lubrication, will be reduced to a minimum.

A still further object of the invention is to so construct frictiondisks, that while all the advantages of lubrication may be procured,theusual attending objection of slippa e will be eliminated.

ccording to the invention, the safety device comprises a shaftoperatively connecting a hoist drum, a member rotatably and slidablymounted on a shaft and operatively connected to power means, an inclinedface safety lowering device,v

on said member, a flange fixedly mounted on said shaft, a ratchetrotatively mounted with respect to said flange, a pressure ringslidmember, and slidably mounted pressure ring will force the saidmember toward the fixedly mounted flange, and thereby exert pres surebetween said member, said ratchet and said flange, and between each ofwhich there a is a friction disk.

The drawings illustrate an embodiment of the invention, and the viewstherein, are as follows Figure 1 is a top plan view of a traveling craneembodying the invention,

Figure 2 is an end elevation of the same,

Figure 3 is a vertical sectional view of the safety lowering devicetaken on the line 3--3 of Figure 1, with a part of the flange brokenaway to reveal the ratchet and pawl,

Figure 4 is a cross sectional view of the safety lowering device takenon the line H of Figure 3,

Figure 5 is a face view of a friction disk,

Figure 6 is a fragmentary similar view showing another form of oilgroove, and

Figure 7 is a perspective view'of the pressure ring.

While .the invention herein disclosed may be embodied in many differenttypes of hoisting machinery, for the purpose of this application it hasbeen shown and will be de scribed in connection with an ordinarytraveling crane.

Referrin to Figure 1, 11 indicates a hoist drum whic is operativelyconnected to the motor 12, through the following mechanism. Suitablegear mechanism (not shown) in the ment 27 of the casing 16. Thatmechanism is shown in vertical section in Figure 4.

Referring now to Figure 2 of the drawings, the crane is provided with ahook 28, having the block 29, which is carried by suitable cables 31,extending over and around the hoist drum 11.

The mechanism shown within the compartment 27, of the casing 16 inFigure 1, and in section in Figure 4, comprises the safety loweringdevice. This device consists generall of a flange 32, having a hub 33,on

' whic is rotatably mounted a ratchet 34, having flanges 36 and 37.Between the flange 32, and the flange 36 of the ratchets, there is afriction disk A.

Rotatably and slidably mounted on the shaft 14, is a member 38, whoseouter peripherial face provides the gear 17, illustrated in Figure 1.This member has an inner face 39, between which and the flange 37 of theratchet 34, there is a friction disk B. These friction disks A and B areidly mounted with respect to the shaft 14.

The hub 41 of the member 38, has an inclined outer face 42, which isshown in the present instance as a helix and a like face 43 on apressure ring 44. This pressure ring is keyed to the shaft 14 by meansof the key 46, which key, however, provides for the sliding movement ofthe said ring on the shaft 14. The shaft 14 is provided with a threadedpart 47 for receiving a nut 48 which positions the pressure ring 44 asdesired.

The ratchet 34 is engaged by a pawl 49 which is pivotally mounted on astub shaft 51. The pawl has a circular hole 52, into which there isfitted a pair of ferrules, or cups 53, with a spiral spring 54, seatedin said cups, and pressing the same outward so as to form a frictionalcontact with the opposed faces of the ratchet flanges 36 and 37.

It will be readily understood, that when the ratchet moves in thedirection shown by the arrow C in Figure 3, the frictional engagement ofthe cups 53 against the opposed faces of the flanges 36 and 37, willcause the pawl to move on its pivoting pin 51, and the tooth 55 thereof,will be thrown out of the ratchet 34, and such frictional engagementwith the said flanges will, in like manner, throw the said tooth intoholding relation with the ratchet 34 when the same operates with theratchet 34, said ratchet will e prevented from rotating.

It is absolutely essential to the construction herein described, thatthe operating parts thereof should be well lubricated. To provide thisnecessary lubrication, oil is placed in the compartment 27, whose levelis such that the lowermost part of the inner diameter of the flanges Aand B will be below that level, so that the said disks will be properlylubricated. 1

If these disks were not lubricated, they would be quickly ground away,and it would be necessary to tear down and reassemble the safetylowering device quite frequently.

The problem which has heretofore confronted engineers, is that ofproperly lubricating these friction disks and at the same time,providing the required friction between them and their co-actingsurfaces. Various methods and means have been suggested. Slots 57 havebeen rovided for returning excessive oil to the Bottom of thecompartment27.

It has been found by intensified experimentation, that a series ofeccentric oil grooves 58 will permit the surfaces, which co-act withsaid disks. to wipe superfluous oil, or lubricating fluid from the facesof said disks and co-acting surfaces so as to allow the faces of'thedisks and co-acting surfaces to provide the proper frictional contactfor efficiently holding the shaft 14 against rotation b the load of thehoist drum, while still provi ing the proper amount of lubrication to(preventing the grinding of the disk faces I an co-acting surfaces.

The present invention also contemplates the use of anti-frictionmaterial in the coacting inclined faces or helices 42 and 43, so thatupon the movement of the shaft 14 in a direction to force said facestogether, the member 38 may freely move longitudinally on the shaft 14and exert the maximum pressure against the flange 32 between which,there is confined the ratchet 34 and friction disks A and B.

The operation of the safety lowering dcvice will be self-evident fromthe explanation of the construction, and the oil wiping effect on thefriction disks provided by the eccentric grooves 58, will provide alowering device with the minimum amount of slippage coupled withlongevity in the friction surfaces.

Figure 6 shows a spiral oil groove 59 which is equally effective forreceiving the'excess oil which is wiped therein from the faces of thedisks and co-operating surfaces.

Of course, the safety lowering device illusand having an inclined faceadapted to co-act with the inclined face of said member for moving saidmember toward said ratchet and flange, friction disks idly mounted withrespect to said shaft on each side of said ratchet and between saidflange and said member and being partially submerged in lubricatingfluid, and eccentric oil grooves arranged to drain and carry offexcessive oil from between the faces of said friction disks and coactingsurfaces.

2. A safety lowering device comprising a shaft operatively connecting ahoist drum, a member rotatably and slidably mounted on said shaft andoperatively connected to ower means, an inclined face on said mom 1', afian e fixedly mounted on said shaft, a ratchet rotatably mounted withrespect to said flange, a pawl fixedly mounted, a pressure ringadjustably mounted on said shaft and havm an inclined face ada ted tocoact with t e inclined face of said member for moving said membertoward said ratchet and flange, friction disks idly mounted with respectto said shaft on each side of said ratchet and between said flange andsaid member and being partially submerged in lubricating fluid, andeccentric oil grooves in the faces of said friction disks arranged todrain and carry off excessive oil from between the faces of saidfriction disks and coacting surfaces.

3. A safety lowering device comprising a shaft operatively connecting ahoist drum, a member rotatably and slidably mounted on said shaft andoperatively connected to power means, an inclined face on said member, aflange fixedly mounted on said shaft, a ratchet rotatably mounted withrespect to said flange, a pawl fixedly mounted, a pressure ringadjustably mounted on said shaft and having an inclined face adapted toco-act with the inclined face of said member for moving said membertoward said ratchet and flange, friction disks idly mounted with respectto said shaft on each side of said ratchet and between said flange andsaid member and being partially submerged in lubricating fluid, andeccentric oil grooves in the faces of said friction disks and co-actingsurfaces for draining and carrying off excessive oil to revent slippage.

4. A sa ety lowering device comprising a shaft operatively connecting ahoist drum, a member rotatably and slidably mounted on said shaft andoperatively connected to power means, a helix on said member, a flangefixedl mounted on said shaft, a ratchet rotatab y mounted with respectto said flange, a pawl fixedly mounted, a pressure ring adjustablymounted on said shaft and having a helix adapted to co-act with thehelix of said member for moving said member toward said ratchet andflange, friction disks idly mounted with respect to said shaft on eachside of said ratchet and between said flan e and sai member and beinpartially su merged in lubricating flui and eccentric oil groovesarranged to drain and carry off excessive oil from between the faces ofsaid friction disks and co-acting surfaces.

5. A safety lowering device comprising a shaft operativel connecting ahoist drum, a member rotata ly and slidably mounted on said shaft andoperatively connected to w'er means, an inclined face formed ofanti-friction material on said member, a flange fixedly mounted on saidshaft, a ratchet rotatably mounted with respect to said flange, a pawlfixedly mounted, a pressure ring adjustably mounted on said shaft andhaving an inclined face formed of anti-friction material adapted toco-act with the inclined face of said member for moving said membertoward said ratchet and flange, friction disks idl mounted with respectto said shaft on eac side of said ratchet and between said flan e andsaid member and being partially su merged in lubricating fluid, andeccentric oil grooves arranged to drain and carry off excessive oil frombetween the faces of said friction disks and co-acting surfaces.

6. A safet lowering device comprising a shaft operatively connecting ahoist drum, a member rotatably and slidably mounted on said shaft andoperatively connected to power means, a helix formed of anti-frictionmaterial on said member, a flange fixedly mounted on said shaft, aratchet rotatably mounted with respect to said flange, a pawl fixedlymounted, a pressure ring adjustably mounted on said shaft and having ahelix formed of anti-friction material adapted to co-act with theinclined face of said member for moving said member toward said ratchetand flange, friction disks idly mounted with respect tosaid shaft oneach side of said ratchet and between said flange and saidsaid frictiondisks partially submerged in lubrieatingT fluid, eccentric oil groovesbetween iction disks and co-operating surfaces for draining and carryingofi excess lubricatin fluid.

8. n a safety lowering device employing load actuated pressure means andmetallic friction disks partially submerged in lubricatin fluid,eccentric oil grooves in the faces of said disks for drainin andcarrying off excess lubricating fluid om between said disks andco-operating surfaces.

9. In a safety lowering device employing load actuated pressure meansand metallic friction disks partially submerged in lubricating fluid,eccentric oil grooves in the faces of said friction disks and in thefaces of said co-operating surfaces for draining and carrying off excesslubricating'fluid from between the same.

10. In a safety lowerin device employing members having helical aces forco-o rative action through a load, and metal isks between parts actedupon by pressure thus produced, said helicesbeing. composed ofanti-friction material and said friction disks being provided witheccentric oil grooves for drainin and carrying ofl' excessivelubricating uid from between said disks and cooperating surfaces.

11. A friction disk fora safety lowering device comprising a plateprovided with eccentric oil grooves, and oil channels connect ing saidgrooves and open at the periphery of said disks for draining thecollected ubrr eating fluid from said rooves.

In testimony," whereo we have signed our names to this s ecification.

vF ANK J. WINTERER.

ARTHUR E. HOGREBE.

